Conventional culture vessels are not designed for physiological oxygen delivery. Both hyperoxia and hypoxia -commonly observed when culturing cells and tissues in regular plastic ware- have been linked to reduced cellular function and death. This is particularly true of pancreatic beta cells, which are highly sensitive to sub- and super-physiological oxygen concentrations. We have addressed this problem by devising a novel culture device, the "oxygen sandwich". This simple system is designed to deliver oxygen in a physiological-like fashion by means of a basal air-permeable perfluorocarbon-silicone (PFC/Si) membrane. Our long-term goal is to establish this system as the new culture standard for beta cell biology applications, a rapidly expanding market that includes in vitro research on adult/fetal islets of any species, as well as beta cell differentiation studies. In this context, the specific aim of this Phase I proposal is to establish proof of concept that the enhanced in vitro survival and function observed in PFC/Si-cultured islets results in better pre-clinical transplantation outcomes. Our research design is based on a marginal mass xenotransplantation model (human islets into diabetic nu/nu immunodeficient mice), where the potential benefits of PFC/Si culture prior to transplantation should translate into a shorter time to diabetes reversal compared to animals transplanted with control (regular culture) islets. Our initial results are strongly supportive of the feasibility of this proposal, and we have partnered with the Diabetes Research Institute at the University of Miami to accomplish our goals in a timely manner. Success in our research would fill a widely acknowledged gap in our ability to preserve islet cell function and survival in vitro, confirming this system as a potential new standard for beta cell biology and differentiation studies. Such positive outcome would be highly relevant to the mission of the National Institutes of Diabetes and Digestive and Kidney Diseases (NIDDK), and might ultimately be of clinical significance for human islet/beta cell transplantation. PUBLIC HEALTH RELEVANCE: Beta cell research is a large field where basic science interest is further fueled by current (islet transplantation) and prospective (stem cells and xenotransplantation) clinical therapies for diabetes. However, beta cell studies are compromised by the inability of conventional culture systems to provide physiological oxygenation. Since our proposal aims at testing a novel culture device specifically designed to overcome this problem, these studies are highly relevant to the mission of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and may ultimately have a significant impact on public health.